CVE-2026-77070 in n8n
Summary
by MITRE • 08/20/2026
n8n before 1.123.69, 2.33.4, and 2.34.1 contains a NoSQL injection vulnerability in the MongoDB node's Find, Delete, and Aggregate operations, which parse the Query parameter as JSON after expression resolution without sanitizing MongoDB operators. An attacker who can influence the resolved query (e.g., via externally-controlled data) can inject operators such as $ne or $where, turning an intended single-document lookup into full-collection disclosure, full-collection deletion, or other operations on the database server.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in n8n versions prior to 1.123.69, 2.33.4, and 2.34.1 represents a critical NoSQL injection flaw within the MongoDB integration node. This security defect specifically affects the Find, Delete, and Aggregate operations when they process user-supplied or workflow-controlled data as query parameters. The core technical issue stems from how n8n handles expression resolution for these database interactions. When an expression is resolved to determine the query criteria, the resulting string is parsed directly into a JSON object without subsequent sanitization of MongoDB-specific operators. This lack of validation allows maliciously crafted inputs that contain special MongoDB syntax to bypass intended filtering logic and execute arbitrary commands against the underlying database instance.
From a technical perspective, NoSQL injection occurs when an application constructs queries using unsanitized user input in non-relational databases like MongoDB. In this specific case, if an attacker can influence any part of the resolved query through externally controlled data sources such as webhooks, HTTP requests, or other workflow nodes, they can inject operators that alter the scope and intent of the database operation. For instance, injecting the $ne operator allows an attacker to bypass equality checks by specifying conditions that match everything except a specific value, effectively disabling filters designed to restrict access to certain records. More dangerously, the injection of the $where operator enables the execution of arbitrary JavaScript code within the context of the MongoDB server. This capability transforms what should be a simple data retrieval or deletion task into a mechanism for full database compromise, including reading sensitive information from all collections or deleting entire datasets indiscriminately.
The operational impact of this vulnerability is severe and multifaceted. An attacker with access to an affected n8n workflow can achieve unauthorized read access to the entirety of the connected MongoDB database, leading to significant data breaches involving personally identifiable information, financial records, or proprietary business logic. Beyond confidentiality losses, the ability to perform full-collection deletions poses a direct threat to data integrity and availability, potentially causing permanent loss of critical organizational assets. Furthermore, if the $where operator is successfully exploited for code execution, it may allow remote command execution on the database server depending on configuration privileges, escalating the breach from data theft to complete system compromise. This vulnerability undermines the fundamental security boundary between the workflow automation layer and the persistent storage backend, exposing organizations to both regulatory penalties under standards like GDPR or HIPAA due to uncontrolled data exposure and operational disruption through destructive actions.
This flaw aligns with CWE-943 Improper Neutralization of Special Elements used in a NoSQL Query (CWE-943), which describes the failure to neutralize special elements that could alter query semantics. In terms of offensive security frameworks, this vulnerability facilitates techniques associated with MITRE ATT&CK T1059 Command and Scripting Interpreter via database queries, particularly when $where is exploited for code execution. It also relates to T1213 Data from Information Repositories where attackers extract data by bypassing access controls through query manipulation. The root cause lies in the assumption that resolved expressions are safe for direct consumption by the MongoDB driver without additional validation layers to filter out dangerous operators or restrict input formats strictly to expected literal values rather than complex query structures when appropriate.
Mitigation strategies must focus on immediate version upgrades and architectural hardening of workflow designs. Organizations running affected versions of n8n should upgrade immediately to 1.123.69, 2.33.4, or 2.34.1 where these input validation checks have been implemented by the developers. For environments unable to patch instantly, defensive coding practices within workflows are essential. Developers must avoid passing raw user inputs directly into MongoDB query parameters without explicit sanitization logic that strips out characters and operators associated with NoSQL injection attacks such as $ne, $gt, $lt, $where, and regex delimiters. Implementing allowlists for expected input formats or using parameterized queries where supported by the driver can significantly reduce risk. Additionally, applying principle of least privilege to the database user account used by n8n ensures that even if an injection occurs, the attacker is limited in their ability to perform destructive actions like dropping collections or accessing unrelated databases. Regular security audits and static analysis tools configured to detect NoSQL injection patterns should be integrated into the development lifecycle to prevent similar vulnerabilities from being introduced in future workflow iterations.